In many industrial production processes a stream containing organic material and sulphate is produced, in particular in production processes wherein organic material and sulphuric acid are used. Examples of such processes are processes which involve the use of sulphuric acid for the release and hydrolysis of lignocellulose, so that the sugar containing groups that are thus produced can be used in a fermentation process for the production of ethanol, lactic acid, citric acid, and the like. Commonly the sulphate in these streams is converted to hydrogen sulphide, in particular using anaerobic treatment processes, after which a step is carried out for removing the hydrogen sulphide.
In the art several processes are known for removing hydrogen sulphide from process gases. U.S. Pat. No. 5,928,620, for example, discloses a process wherein H2S is converted to elemental sulphur.